Niraparib PHONIRA 100mg: Biomarker-Defined Maintenance in Ovarian Cancer

Overview

Niraparib is a PARP inhibitor used as maintenance therapy, and its population is defined by biology rather than by symptoms alone. It is offered to ovarian cancer patients whose tumors carry BRCA mutations or show homologous recombination deficiency, and more broadly to those who have responded to platinum-based chemotherapy. The idea is to delay the next relapse in a molecularly selected group. Because the benefit is tied to DNA-repair status, biomarker results guide who starts the drug and at what dose, making patient selection the heart of how the therapy is used in clinical practice today.

How It Works

Niraparib traps PARP at sites of DNA damage and blocks base-excision repair. In tumors that already lack homologous recombination, such as BRCA-mutated or HRD-positive cancers, the accumulated unrepaired damage becomes lethal while normal cells, with intact repair, tolerate the block. This synthetic-lethal effect is why the drug works best in the repair-deficient population and why testing precedes therapy, so patients without the biomarker are not exposed to myelosuppression without a clear expected benefit.

Indications

• Maintenance treatment of recurrent ovarian, fallopian tube or primary peritoneal cancer after platinum response
• First-line maintenance in stage III to IV disease per label
• Used in BRCA-mutated or HRD-positive populations and beyond

Dosage & Administration

The starting dose is 300 mg once daily, three 100 mg capsules, for patients weighing at least 77 kg with platelets of at least 150,000 per microliter; others start at 200 mg daily. Treatment continues until progression or limiting toxicity, with blood counts guiding any holds or reductions along the way, and the lower start in smaller patients reflects the tighter safety margin seen in that subgroup during registration studies.

Storage & Sourcing

Store at 20 to 25°C in a dry place. Supplied through TLP, Beacon and Everest partner lines as GMP capsules with lot-specific certificates of analysis. As an ambient-stable oral product it is straightforward to distribute to oncology pharmacies for maintenance care, and capsule blistering keeps each dose protected during transit and at home between clinic visits.

FAQ

Q: Which patients benefit most from niraparib?

A: Those with BRCA mutations or HRD-positive tumors, and more broadly any patient who has responded to platinum chemotherapy, per the approved maintenance indication.

Q: How is the dose individualized?

A: Body weight and platelet count guide the start: 300 mg daily for heavier patients with adequate platelets, 200 mg for others, balancing efficacy against blood-count safety.

Q: Why is it called maintenance therapy?

A: It is given after chemotherapy has controlled the disease to delay the next relapse, not as primary treatment for actively progressing cancer.

Q: What blood tests matter during treatment?

A: Regular complete blood counts track myelosuppression; dose holds or reductions manage low platelets or hemoglobin as they appear.